The presence and levels of certain types of toxins in the body of an individual is indicative of the consumption of certain substances which are known to impair the performance capability of an individual. In industry, the level of certain toxins in the body of an employee is used to determine the employee's capability to perform on the job, whether the employee can perform the job safely and whether the employee is in compliance with company policy regarding use Of substances (such as alcohol or cocaine) which produce the toxins. In the medical field the presence of toxins is known to aid in the determination of the origin of loss of motor function and life-threatening coma. In the legal field the specific level of certain toxins in the blood stream is used as an objective indicia of fitness to operate machinery or to drive an automobile or other vehicles. It is particularly important for law enforcement purposes to have simple, fast, convenient, automated qualitative methods of determining whether there are toxins in an individual's blood system such as alcohol and cocaine or metabolites of such substances.
Known methods of integrating a toxin-testing device into a vehicle have been problematic. Examples of such problematic devices are disclosed in U.S. Pat. No. 4,093,945 and U.S. Pat. No. 3,886,540.